Editor: Change location of block support styles in wp_head.

Backports changes from WordPress/gutenberg#39164.

Props ndiego, alexstine, cbravobernal, mamaduka.
Merges [53015] to the 5.9 branch.
See #55474.

Built from https://develop.svn.wordpress.org/branches/5.9@53017


git-svn-id: http://core.svn.wordpress.org/branches/5.9@52606 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/script-loader.php

@@ -2925,8 +2925,8 @@ function wp_enqueue_global_styles_css_custom_properties() {
  *
  * For block themes, it's loaded in the head.
  * For classic ones, it's loaded in the body
- * because the wp_head action (and wp_enqueue_scripts)
- * happens before the render_block.
+ * because the wp_head action happens before
+ * the render_block.
  *
  * @link https://core.trac.wordpress.org/ticket/53494.
  *
@@ -2935,7 +2935,7 @@ function wp_enqueue_global_styles_css_custom_properties() {
 function wp_enqueue_block_support_styles( $style ) {
 	$action_hook_name = 'wp_footer';
 	if ( wp_is_block_theme() ) {
-		$action_hook_name = 'wp_enqueue_scripts';
+		$action_hook_name = 'wp_head';
 	}
 	add_action(
 		$action_hook_name,

wp-includes/version.php

@@ -16,7 +16,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.9.3-alpha-53013';
+$wp_version = '5.9.3-alpha-53017';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.